JPH06100760B2 - Viewfinder switching mechanism for dual-focus camera - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a viewfinder switching mechanism of a two-focal point switching camera, which is capable of switching the focal length in two steps by switching between two taking lenses having different focal lengths.

(Prior Art) There is a two-focal point switching camera that has photographing lenses with different focal lengths and can switch the focal lengths in two stages by switching the photographing lenses. In such a camera, it is necessary for the finder to switch the incident angle in response to the lens switching.

In the conventional viewfinder switching mechanism in such a camera, the lenses forming the viewfinder are moved in parallel. Therefore, it is necessary to secure a large space for the lens to move, and the camera becomes large and the operation force is relatively large. There is a problem that it requires.

(Object) It is an object of the present invention to provide a viewfinder switching mechanism for a two-focus switching camera, which has a small lens moving space, can be downsized, and has a small amount of power required for switching.

(Structure) The present invention is directed to a light flux that is disposed on the optical axis of the first taking lens, the second taking lens, and the second taking lens that have different focal lengths, and is transmitted through the second taking lens. A fixed mirror that reflects the light toward the rear of the first taking lens,
A rotary mirror disposed behind the first photographing lens on the optical axis of the same lens and reflecting a light flux reflected from the fixed mirror toward an image forming position surface; In a viewfinder switching mechanism of a bifocal switching camera configured to switch the focal length of the taking lens by switching the optical paths of the taking lens and the second taking lens, the taking lens light is centered on an axis parallel to the taking lens optical axis. An external switching member that rotates in a plane perpendicular to the axis, a switching lever mechanism that switches the focal length of the photographing lens by rotating the rotary mirror in conjunction with the switching operation of the external switching member, and the switching lever mechanism. The objective lens for the finder and the eyepiece that are provided so as to move forward and backward on the optical path of the finder by rotating By the switching operation of the external switching member, the objective lens and the eyepiece lens both move into the viewfinder optical path in conjunction with the switching lever mechanism, and the objective lens and the eyepiece lens both retract from the viewfinder optical path. It is characterized by being configured as follows.

Hereinafter, the present invention will be described with reference to the illustrated embodiments.

In FIGS. 1 and 2, a cartridge loading chamber 85 is provided in the lower portion of the camera body 1, and a spool chamber 86 having the take-up spool 4 is provided in the upper portion of the camera body 1. The film 3 pulled out from the pressure plate 5
The spool 4 is wound up through the position of. A shutter substrate 6 is fixed to the front side of the camera body 1. A lens barrel frame 7 is fixed to the back side of the shutter substrate 6. A switching mechanism substrate 12 is fixed between the camera body 1 and the lens barrel frame 7. Two helicoids 11, 17 are formed side by side on the lens barrel frame 7, and the helicoids 11, 17 are formed.
Lens barrels 8 and 16 are respectively screwed into the. A lens 9 having a relatively short focal length (hereinafter referred to as a “wide-angle lens”) 9 as a first taking lens is fitted in the lens barrel 8, and a relatively focal length as a second taking lens is provided in the lens barrel 16. A long lens (hereinafter referred to as "telephoto lens") 18 is fitted.
The shutter substrate 6 has a window hole in front of each lens 9 and 18.
87 and 88 are formed. A shutter curtain 10 is provided between the shutter substrate 6 and the lens barrel frame 7 to open and close the front of the lenses 9 and 18.

The surface of the film 3 in front of the pressure plate 5 forms an image forming position 89, and a first mirror 20 as a rotating mirror is rotatable about an axis 21 between the image forming position 89 and the wide-angle lens 9. By being held by the first mirror frame 19, it is provided so as to be able to move forward and backward along the optical path of the wide-angle lens 9. The first mirror frame 19 is provided so as to be rotatable in the horizontal direction (the direction parallel to the paper surface in FIG. 2), and when the mirror frame 19 is in the optical path of the wide-angle lens 9 as shown in FIG. The protrusion 36 of the adjustment screw 37
The position of the first mirror 20 is regulated by making contact with the. A second mirror 35 as a fixed mirror is obliquely provided behind the telephoto lens 18 by being held by a second mirror frame 34. The mounting angle of the mirror frame 34 is adjusted by the adjusting screw 38.
As shown in FIG. 2, when the first mirror 20 is in the optical path of the wide-angle lens 9, the light passing through the wide-angle lens 9 is blocked, while the light passing through the telephoto lens 18 is blocked by the second mirror 35 and the second mirror 35. 1
The light is reflected by the mirror 20 and guided to the image forming position 89. Further, when the first mirror 20 rotates and retracts from the optical path of the wide-angle lens 9, the light passing through the wide-angle lens 9 is directly guided to the image forming position 89.

A pin 22 is provided on one side surface of the first mirror frame 19, and the pin 22 is fitted in a fork portion 25 at one arm end of the first switching lever 23. The lever 23 is provided so as to be horizontally rotatable about a shaft 24. A fork portion 26 is formed on the other arm end portion of the lever 23, and a pin 29 of one arm of the second switching lever 27 is fitted in the fork portion 26. Lever 27 is shaft 28
It can be rotated in the horizontal direction. Lever 23 and lever
A reversing lever 31 is provided near the connecting portion of 27 so as to be rotatable in the horizontal direction around a shaft 32. The reversing lever 31 has an arcuate edge portion and is urged to rotate by a spring 33 so that the arcuate edge portion is pressed against one arm end of the second switching lever 27. The reversing lever 31 is based on the elasticity of the spring 33, the lever 27, the lever 23 that interlocks with the lever 27, and the first mirror.
This is for causing the 20 to perform a kind of click operation, and in the position as shown in FIG. 2, the lever 27 is rotated counterclockwise by the arcuate edge portion of the lever 31, so that the lever 23 and When the first mirror 20 is held in the position shown in the drawing and the lever 27 is rotated clockwise in FIG.
After the abutment point between 31 and lever 27 exceeds the speculation point, lever 31
Urges the lever 27 to rotate clockwise, the lever 23 to rotate counterclockwise, and the first mirror 20 to rotate clockwise. The switching mechanism including the levers 23, 27 and 31 is provided on the switching mechanism substrate 12 shown in FIG.

In FIG. 1, reference numeral 13 is a parallax lever, and 14 is a wide-angle focusing lever. In FIG. 2, reference numerals 42 and 43 are respectively a finder objective lens and an eyepiece lens, 44 is a parallax mask, and 45 is a third switching lever.

3 and 4 show details of the support mechanism for the second mirror 35. A mirror frame seat 39 is fixed to the lower surface of the switching mechanism substrate 12, and a second mirror frame 34 is rotatably supported by shafts 40 that are passed through both bent ends of the mirror frame seat 39. The second mirror frame 34 is rotationally biased by a spring 41. The second mirror 35 protruding laterally from the second mirror frame 34 is contacted with the adjusting screw 38 from the rear surface side to restrict the rotation of the second mirror frame 34 by the urging force of the spring 41, and thus the second mirror 35. The inclination angle of is set.

FIG. 5 shows details of the support mechanism for the first mirror 20. In FIG. 5, the shaft 21 is vertically supported between the two projecting pieces 90, 90 of the lens barrel 7, and the shaft 21 allows the mirror frame 19 integrally including the first mirror 20 to rotate in the horizontal direction. Supported by. As already explained with reference to FIG. 2, the first mirror frame
A projecting portion 36 is formed on one side edge portion of 19 and the turning position of the first mirror 20 is regulated by the adjustment screw 37 hitting the projecting portion 36.

FIG. 6 is a front view of the lens switching operation section and the finder section. In FIG. 6, a circular barrier 53 as an external switching member is provided on the front surface of the camera so as to be rotatable about a shaft 54 in a vertical plane. The barrier 53 is formed with a radius that allows the front of the wide-angle lens 9 and the telephoto lens 18 to be contained with a margin.
The barrier 53 has a window hole 55 at a position off the axis 54.
The barrier 53 is rotatable in a range of about 180 degrees, and when the barrier 53 is at the end position of this rotating range, the window hole 55 is located in front of the wide-angle lens 9 or the telephoto lens 18. A fourth switching lever 50 is provided on the shutter substrate 6 (see FIGS. 1 and 2) so as to be vertically rotatable about a shaft 52. The one arm 77 of the lever 50 is on the passage of the pins 75 and 76 provided on the inner surface side of the barrier 53, and when the barrier 53 is rotated clockwise or counterclockwise in the figure to the end position, the pin 76 or the pin 75 is moved. The one arm 77 is pushed to rotate the lever 50 clockwise or counterclockwise. Lever 50
A bent portion 51 is formed at the other end of the arm, and the bent portion 51 is engaged with the window hole 48 of one arm of the third switching lever 45.

The third switching lever 45 is formed in an inverted U shape as shown in FIG. 9 and has two arms 91 having a shaft 47 as a common shaft.
A bent portion 82 is formed at the tip portion of one arm 91, the window hole 48 is formed at the tip portion of the other arm 92, and the pin 72 is fixedly planted. Another window hole 46 is formed on the surface perpendicular to the surface on which 48 is formed.

A lever mechanism including a first switching lever 23, a second switching lever 27, a third switching lever 45, and a fourth switching lever 50 rotates the first mirror 20 to move the mirror 20 forward and backward on the optical path of the wide-angle lens 9. It constitutes a switching lever mechanism.

In FIG. 6, in front of the third switching lever 45, an objective lens holding lever 70 having an objective lens 42 at its tip is provided with a shaft 69.
Is provided so as to be rotatable in a vertical plane. lever
The spring 70 is rotationally biased by a spring 71, and the biasing force presses one side edge portion against the pin 72 of the lever 45. Objective lens
42 is movable back and forth on the optical path of the finder by the rotation of the lever 70.

In FIGS. 6 and 7, the parallax lever 13 is provided on the substrate 12 in the left-right direction. The pin 60 fixed to one end of the lever 13 penetrates the long hole of the substrate 12 and is located laterally of the bent portion 59 formed on the focusing lever 14 with a wide angle. The focusing lever 14 is a pin that penetrates the arc-shaped elongated holes 56, 56.
57, 57 are fixedly planted on the shutter substrate 6 so that the long holes 5
It is provided so that it can rotate in a vertical plane within the range allowed by 6 and 56. The focusing lever 14 is biased by a spring 58 so as to rotate in one direction. A bent portion 61 is formed at the other end of the parallax lever 13, and a parallax drive lever 62 having a shaft 63 as a rotation center is extended to the side of the bent portion 61. The parallax drive lever 62 is pivotally attached to the parallax mask 44 on a shaft 66, the parallax mask 44 is pivotally attached to a parallax driven lever 64 on a shaft 97, and the parallax driven lever 64 is rotatable about a shaft 65. It is provided in. The portion including the lever 62, the parallax mask 44, and the lever 64 constitutes a four-bar link, and when the bent portion 61 moves due to the movement of the parallax lever 13, the lever 62 follows and the mask 44 moves in parallel. The window 67 is adapted to move in parallel in an oblique direction. The lever 64 is rotationally biased by a spring 68 so that the four-joint link is driven by the movement of the parallax lever 13. As shown in FIG. 10, the mask 44 is an objective lens of the finder optical system.
Behind 42.

The pin 74 fixed near the bent portion 61 of the parallax lever 13 penetrates the substrate 12 and engages with the parallax follower 73. The parallax follower 73 is provided so as to be rotatable about the shaft 28, and the substrate 12 is also provided via the shaft 28.
It is provided substantially integrally with the upper second switching lever 27. The pin 30 fixed to one arm of the lever 27 is engaged with the window hole 46 of the third switching lever 45 (see FIG. 2).

As shown in FIGS. 1 and 2, the focusing lever 14 is integrally attached to the lens barrel 8 of the wide-angle lens 9, and when the lens barrel 7 is rotated together with the lever 14, the lens barrel 7 is moved. Helicoid 11
Is guided to move forward and backward together with the wide-angle lens 9 for focusing. A focusing button 15 is provided on the focusing lever 14, and the focusing on the wide angle side is performed by aligning the focusing button 15 with the zone focus mark.

Although not shown, a focusing lever is also integrally provided on the telephoto side lens barrel 16, and focusing on the telephoto side is performed by aligning the operation button of the focusing lever with the zone focus mark. It's getting better. However, the focusing mechanism on the telephoto side is not linked to the parallax adjustment mechanism.

In FIG. 8, one arm end 81 of an eyepiece lens holding lever 78 with a shaft 79 as a rotation center is attached to a bent portion 82 of one arm 91 of the third switching lever 45 by a spring 80. Pressed by power. The lever 78 integrally includes the eyepiece lens 43. The eyepiece lens 43 is movable back and forth on the finder optical path by the rotation of the lever 78.

Next, the operation of the above embodiment will be described separately for the telephoto mode and the wide-angle mode.

Telephoto mode As shown in FIG. 2, when the first mirror 20 is advanced behind the wide-angle lens 9 to block the optical path of the wide-angle lens 9, the barrier 53 shown in FIG. Windows 55
Is located in front of the telephoto lens 18, light from the subject that has passed through the window hole 55 reaches the telephoto lens 18 through the window hole 88 of the shutter plate 6 and passes through the telephoto lens 18. Is reflected by the second mirror 35 toward the first mirror 20, is further reflected by the first mirror 20, is guided to the image forming position 89, and the subject image is formed at the image forming position 89.

In this telephoto mode, the barrier 53 is rotated clockwise in FIG. 6 and its pin 76 pushes the arm 77 of the lever 50 to rotate the lever 50 clockwise, and the other arm of the lever 50 is bent. The portion 51 pushes the edge of the window hole 48 of the lever 45 to rotate the lever 45 counterclockwise in FIG.
72 pushes one side edge of the lever 70 to rotate the lever 70 counterclockwise against the urging force of the spring 71, thereby retracting the objective lens 42 from the finder optical path. Also, by the above-mentioned rotation of the lever 45, the bent portion 82 pushes the arm end portion 81 of the lever 78 as shown in FIG. 8 to rotate the lever 78 in the clockwise direction against the spring 80. The eyepiece lens 43 is retracted from the viewfinder optical path. Therefore, as shown in FIG. 10 (3), the viewfinder simply has the objective window 83 and the eyepiece window 84, and constitutes a plain viewfinder. Focusing in the telephoto mode is performed by operating a focusing mechanism (not shown). There is no parallax adjustment mechanism in telephoto shooting, so there is no parallax adjustment mechanism.

Wide-angle mode When switching from the telephoto mode to the wide-angle mode, the barrier 53 is rotated counterclockwise in FIG. During the rotation of the barrier 53, the internal mechanism does not change at all, and both the wide-angle lens 9 and the telephoto lens 18 are simply shielded by the barrier 53. When the barrier 53 is rotated counterclockwise in FIG. 6 to the end, the pin 75 of the barrier 53 moves to the arm 77 of the lever 50.
Press to rotate the lever 50 counterclockwise. The rotation of the lever 50 causes the lever 45 to rotate in the clockwise direction, and the lever 70 follows the rotation in the clockwise direction, and the objective lens 42 advances into the finder optical path. Further, following the rotation of the lever 45, the lever 78 in FIG. 8 rotates counterclockwise by the urging force of the spring 80, and the eyepiece lens 43 advances into the finder optical path. In this way, the viewfinder becomes as shown in FIG. 10 (1), and the viewfinder having the incident angle suitable for the incident angle of the wide-angle lens 9 is switched.

On the other hand, the above rotation of the lever 45 causes the lever in FIG.
27 is clockwise, lever 23 is counterclockwise, and
The mirror 20 is rotated clockwise about the axis 21 of the frame 19, and the mirror 20 is retracted from the optical path of the wide-angle lens 9. During the rotation of the lever 23, the turning force of the reversing lever 31 based on the elastic force of the spring 33 is switched to the direction for urging the lever 27 to rotate in the clockwise direction, so that the first mirror 20 moves in the clockwise direction. Will be retained. First mirror 20
By the above rotation of the first mirror 20, the first mirror 20 is retracted from the optical path of the wide-angle lens 9. Due to the rotation of the barrier 53, the window 55 is located in front of the wide-angle lens 9, and the light incident on the wide-angle lens 9 through the window 55 and the window 87 of the shutter plate 6 is directly in the image forming position. Guided to 89, shooting in wide-angle mode.

Focusing in the wide-angle mode is performed by operating the focus button 15 to rotate the lens barrel 8 integrally with the focus lever 14 and moving the wide-angle lens 9 back and forth by guiding the hecoid 11. Then, the parallax lever 13 moves to the left and right in FIG. 6 following the rotation operation of the focusing lever 14. When the subject distance focused by the wide-angle lens 9 falls within a short range, the lever 62 rotates following the movement of the lever 13 within that range, and the parallax mask 44 that constitutes a link mechanism together with the lever 62. Shifts diagonally, and as a result, as shown in FIGS. 10 (2) and 11, the window hole 67 appearing in the finder field shifts diagonally, and parallax adjustment is performed.

Switching from the wide-angle mode to the telephoto mode is performed by rotating the barrier 53 in the clockwise direction in FIG. 6 and setting the switching lever mechanism in the rotational position as shown in FIGS. 6 and 2. In the middle of the rotation of the barrier 53, both the wide-angle lens 9 and the telephoto lens 18 are shielded by the barrier 53 and the switching lever mechanism does not change.
Only at the final stage of the rotation of the barrier 53, the fourth switching lever 50 is pushed around the pin 75 and the switching operation as described above is performed.

(Effect) According to the present invention, the objective lens and the eyepiece of the finder corresponding to the switching of the photographing lenses having different focal lengths are switched by rotating the objective lens and the eyepiece. As compared with the conventional one in which the lens is moved in parallel for switching the finder, the space occupied by the lens is small and the size can be reduced. Further, there is an effect that the amount of power required for switching is smaller than that of a lens in which the lens moves in parallel.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention, FIG. 2 is a lateral sectional view of the same as above, FIG. 3 is a side view showing details of a second mirror portion in the above embodiment, and FIG. 5 and 5 are side views showing details of the first mirror portion in the above embodiment, FIG. 6 is a front view showing the above embodiment, and FIG. 7 is a part of the switching lever mechanism in the above embodiment and FIG. 8 is a plan view showing a part of the focusing mechanism, FIG. 8 is a front view showing a part of the finder switching mechanism in the above embodiment, and FIG. 9 is one of the levers constituting the switching mechanism in the above embodiment. FIG. 10 is a perspective view, FIG. 10 is an optical layout diagram showing various switching modes of the finder of the above embodiment, and FIG. 11 is a viewfinder view showing a state of parallax adjustment in the above embodiment. 9 ... Wide-angle lens (first shooting lens), 18 ... Telephoto lens (second shooting lens), 20 ... First mirror, 35 ...
Second mirror, 42 ... Objective lens, 43 ... Eyepiece lens, 53
…… Barrier (external switching member), 23, 27, 45, 50 ……
Switching lever that constitutes the switching lever mechanism, 89 ......
Imaging position.

Claims (2)

[Claims] 1. A first taking lens and a second taking lens having different focal lengths.
A fixed mirror which is arranged on the optical axis of the second photographing lens and the second photographing lens and which reflects the light flux transmitted through the second photographing lens toward the rear of the first photographing lens; A photographing mirror disposed behind the photographing lens on the optical axis of the photographing lens and reflecting a light flux reflected from the fixed mirror toward an image forming position, and by rotating the rotating mirror, a first photographing lens and A bifocal switching camera configured to switch the focal length of the taking lens by switching the optical path of the second taking lens, wherein the camera is rotated on a plane perpendicular to the taking lens optical axis about an axis parallel to the taking lens optical axis. An external switching member, a switching lever mechanism that switches the focal length of the photographing lens by rotating the rotating mirror in conjunction with the switching operation of the external switching member, and the switching It has an objective lens for the finder and an eyepiece lens which are provided so as to advance and retreat on the optical path of the finder by rotating in conjunction with the lever mechanism, and in conjunction with the switching lever mechanism by the switching operation of the external switching member, A finder switching mechanism, characterized in that both the objective lens and the eyepiece lens are configured to advance into the finder optical path and both the objective lens and the eyepiece lens are retracted from the finder optical path. 2. The objective lens and the eyepiece lens of the finder are advanced into the finder optical path in the short focus mode, and the objective lens and the eyepiece lens are retracted out of the finder optical path in the long focus mode. The finder switching mechanism described in the first item of the range.